Process and apparatus for making safety glass



Aug. 31, 1937. w. ow-:N 2 ,091,331

PROCESS AND APPARATUS FOR MAKING SAFETY GLASS BY au TORNEYS.

Parma. Aug. 31, 1937 2,091,331

UNITED STATES PATENKT OFFlCE PROCESS AND APPARATUS FOR MAKING i SAFETY GLASS William Owen, Pittsburgh, Pa., assignor to Pittsburgh Plate Glass Company, a corporation of Pennsylvania Application January 8, 1936, Serial No. 58,127

Claims. '(Cl. 49-81) The nvention relates to a process and appa-- essary to attach the glass sheets to the interratus for making safety glass continuously in a layer, the heat and pressure serving to soften Straight away operation. It is illustrated and the resin and cause it to adhere to the glass described in the production of glass in which the sheets. Various kinds of resin may be employed 5 interlayer is of synthetic resin, or the like, which as'is well known in the art, the resin preferably 5 may be secured to the glass by the application of used being a vinyl acetal. It -is also possible heat and pressure without the use of cement, to use one of the cellulose derivative plastics, but it Will be understood that interlayers which such as cellulose nitrate, cellulose acetate or ethyl require cement may be utilized by coating the celluose, but in this case, some cement is necesfaces of the glass sheets with a cement, such sary in order to secure attachment between the 1 as gelatine, which becomes active When' the sandglass'and the interlayer, This cement is applied wich is exposed to heat and pressure. The into the faces of the glass sheets preliminary to vention has for its objects the provision of an their application to the interlayer, and the heat improved apparatus and process which may be and pressure which is supplied in the passage of operated more rapidly and with less manual the sandwiches through the press serves to sof- 15 labor than the intermittent processes now-uniten the cement so that adhesion is Secured beversally employed, which requires a relatively tween the 'glass and interlayer. limited factory space, and which may be used The interlayer 5 is indicated in the present in connection with a continuously formed intercase as being formed continuously coincident layer. One embodiment of the apparatus hich with its application as an interlayer. The method 2" may be used for carrying out the process is illusof formation is immaterial in so far as the prestrated in the accompanying drawings, wherein: ent nvention is concerned. After formation, the

Figure 1 is a vertical section through the comsheet pas es ar t e n rine or c ine plete apparatus. And Fig. 2 is a Vertical section rolls ll which are suitably heated and then over on an enlarged scale through a portion of the the roller runway l2 and between a pair of rolls 2 apparatus. I3, after which it moves downward through the Referring to the drawings, l,- 2, 3, and 4 are Slot l4 and through the roller press. At the upwork floors of a structure in which the appaper end of the roller press is a pair of assemratus is installed. In carrying out the operation, bling rolls |5 similar in construction to the rolls a sheet of reinforcing material 5, which is to conof the press, but of larger size and provided with sttute the interlayer in the laminated units, is stop members in t e for Of dg te carried continuously downward through a roller longtudinally of the rolls (Fig. 2) which serve press, pairs of glass sheets being applied in seto engage the lower edges of the glass sheets preries to the opposite sides of the interlayer prelimnary CO their eplflicatmh to the nterlayel' liminary to its passage through the press. A and insure that the lower edges of such sheets space is left between the successive pairs of shall be in alinement. The diameter of the rolls sheets, as applied to the interlayer, and after iS qu 0 t Wdth f the glass sheets DlIlS each unit emerges from the bottom of the press, the space Which iS 13 e p v d between Suethe interlayer is severed and the composite plate SS V pa s Of SheetS- MOImted 130 Swing 3100111? 40 i placed upon a receiving rack, the axes of the rolls l5 are a pair of roller tables 40 The roller press is of a type well known in ll, ll adapted to Swing fromahorizontal position the art except that its position is Vertical instead to the uprigh DOSitOh at d in Fg. 1. The of horizontal. It comprises a casing 6 in Which ss sh s are plied to the win i e l s are mounted pairs of opposing presser rolls 1, When ey are n hOrZOntl D H, d When 5 1. As indicated in Fig. 2, these rolls consist of y are SWllng to p t position, the lower` pipe sections 8 each provided with a rubber cover ed es of the sheets engage the StODS IG. Up n a 9. Intermediate the successive pairs of rolls further IOtatiOII Of the o the ss s eets are suitable heating means. As h n, th se move downward therewth and are brought into consist of resistance elements Ela in refiectors IO, e a eme t With the interlayer so that they are current being supplied through the element t fed downward between the rolls l5 and then 50 f provide the necessary heat. It wm b d carried through the roller press as heretofore stood that any other suitable form of heater may described. be employed and that the rolls are driven by The roller tables `are oscillated from horimeans which are not shown. If a Synthetic zontal to Vertical position by means of a crank resin is used as an interlayer, no cement is nec- |8 connected with the right hand t le IT by 55 means of the link 9, the crank being driven from an electric motor through the intermediary of suitable reduction gearing in the oasing 2I. The shafts of the two rolls |5, l5 carry intermeshing spur gears 22, 22 so that the table H to the left of the interlayer is moved with the other table by reason of the gear connection. The glass sheets are delivered to the table IT, ll on roller runways 23, 23, which extend through washers 24, 24 and heaters 25, 25. Intermediate the washers and heaters are drying means consisting in each case of a suction nozzle 26 and a blower nozzle 21 operated from the power driven blowers 28. The glass sheets are supplied to the roller runways 23, 23 from the racks 29, 29 and carried through the washers and heaters where the sheets are cleaned and dried, and then run onto the swinging tables ll, ll. The operation is so timed that the glass sheets are supplied by the swnging tables to the forwardly moving interlayer at uniform intervals of' about one inch. The sandwiches Which are formed emerge from the bottom of the roller press casing and are received upon a yielding foot 30 pressed upward by a spring 3I. A rack 32, which is slghtly inclined and provided with rollers, avoids any danger of the plates tilting to the left after they are received upon the foot 30. As the sandwich emerges from the bottom end of the casing, the interlayer is separated by a workman stationed at this point, the cutting operation being preferably carried on by means of a knife. As each sandwich is separated, it is removed to the right and placed upon a rack 33. It will be understood that any suitable cutting means may be employed at the lower end of the casing, as a substitute for the hand operation as above described. Since the Workman is required at this point to remove the completed plates, there is no great advantage in cutting off other than by ahand operation.

While the operation is preferably practiced, as shown, With a downward feed through the roller press and With gravity assisting the feed 7 through the press, this movement might be reversed with the feed upward through the press and with an application of the glass sheets. at the bottom end of the press casing. The interlayer may also be supplied from large rolls of the material instead of being supplied coincident with the production of the sheet as heretofore desribed.

What I claim is:

1. A process of making safety glass Which consists in feeding an interlayer of non-shatter material continuously downward, applying pairs of sheets of glass in series to the opposite sides of the interlayer with cutting spaces between the successive pairs of sheets, subjecting each pair of sheets to heat and to a progressive roller pressing action as they move downward, and finally severing the interlayer at the spaces between the successive pairs of sheets.

aosztss 2. Apparatus for making safety glass, a roller press comprising a series of presser rolls arranged in pairs one above the other to provide a Vertical pass, means for feeding a continuous sheet of non-shatter material downwardly through the pass, means for applying to the opposite sides of the sheet before it reaches said pass a series of pairs of glass sheets, stop means at the upper end of the said pass for aligning the lower edges of each pair of glass sheets as they enter the pass, and means for applying heat to the series of pairs of sheets as they progress through the pass between the rolls. v

3. Apparatus for making safety glass, a roller press comprising a series of presser rolls arranged in pairs one above the other to provide a Vertical pass, means for feeding a continuous sheet of non-shatter' material through the pass, a table on each side of the roller press at the inlet end thereof, each pivoted at its end next to the press and adapted to swing from a horizontal position to an upright position closely adjacent the line of travel of said interlayer so that the tables apply a series of pairs of glass sheets to said continuous sheet, and means for applying heat to the series of pairs of sheets as they progress through the pass between the rolls.

4. Apparatus for making safety glass, a roller press comprising a series of presser rolls arranged in pairs one above the other to provide a Vertical pass, means for feeding a continuous sheet of non-shatter material through the pass, a table on each side of the roller press at the inlet end thereof, each pivoted at its end next the press and adapted to swing from a horizontal position to an upright position closely adjacent the line of travel of said continuous sheet, a horizontal runway in alinement With each of said tables when they are in horizontal position for de1iver-' ing glass sheets thereto, means for oscillating the tables back and forth between their horizontal and Vertical positions so as to apply the glass sheets carried thereby in pairs to said continuous sheet, and means for heating the pairs of sheets as they progress between the rolls of the press.

5. Apparatus for making safety glass, a roller press comprising a series of presser rolls arranged in pairs one above the other to provide a Vertical pass, means for feeding a continuous sheet of non-shatter material downwardly through the pass, means for applying to the opposite sides of said sheet above the press a series of pairs of glass sheets, stop means carried by the upper pair of rolls for aligning the lower edges of each pair of sheets as they move into the pass, and means for applying heat to the series of pairs of sheets as they progress through the pass between the rolls. 1

WILLIAM OWEN. 

